Detect use after free and report instead of VERIFY (#26434)

Author: pavelvelikhov

ydb/core/kqp/compile_service/kqp_compile_actor.cpp

@@ -438,8 +438,8 @@ class TKqpCompileActor : public TActorBootstrapped<TKqpCompileActor> {
     void InternalError(const TString message) {
         ALOG_ERROR(NKikimrServices::KQP_COMPILE_ACTOR, "Internal error"
             << ", self: " << SelfId()
-            << ", message: " << message);
-
+            << ", message: " << message
+            << ", query text: " << QueryId.Text);
 
         NYql::TIssue issue(NYql::TPosition(), "Internal error while compiling query.");
         issue.AddSubIssue(MakeIntrusive<TIssue>(NYql::TPosition(), message));

yql/essentials/core/yql_gc_transformer.cpp

@@ -29,6 +29,8 @@ class TGcNodeTransformer : public TSyncTransformerBase {
                 const auto range = ctx.UniqueNodes.equal_range(hash);
                 for (auto jt = range.first; range.second != jt;) {
                     if (jt->second == dead) {
+                        YQL_ENSURE(jt->second->UseCount()==0);
+                        YQL_ENSURE(jt->second->Dead());
                         jt = ctx.UniqueNodes.erase(jt);
                     } else {
                         ++jt;